This application claims the benefit of priority under 35 U.S.C. xc2xa7 119 (a) of Taiwan Patent Application No. 089 126153, filed December 2000.
1. Field of the Invention
The invention relates generally to a computer system for multi-type DRAM support, in particular to a computer system that supports DDRAM (Dual Data Random Access Memory) and SDRAM (Synchronous Dynamic Random Access Memory).
2. Description of the Related Art
DDRAM coupled with 184 pin dual in line memory module (DIMM) slot is expected to be one of the mainstream of dynamic random access memory (DRAM). However, a change of the memory module specification is occurring. DDRAM, inserted in a 184 pin DIMM slot, is gradually taking up the market that is formerly occupied by the SDRAM, inserted in a 168 pin DIMM slot.
Due to the difference of the pin assignment between 184 pin DIMM and 168 pin DIMM, a prior art computer system cannot support both DDRAM with 184 pin DIMM and SDRAM with 168 pin DIMM at one time. During the market shifting from one specification to the other, such problem can cause troubles for users regarding computer system upgrading and purchase decision of computer system.
It is therefore a primary objective of the present invention to provide a computer system, which supports both DDRAM and SDRAM, to solve the above-mentioned problems.
In a preferred embodiment, the present invention provides a computer system for multi-type DRAM support includes a first slot for receiving a first type DRAM, a second slot for receiving a second type DRAM, a north bridge chip, and a control circuit. The first slot includes a plurality of first slot pins, and each of them corresponds to a first pin assignment. The second slot includes a plurality of second slot pins, and each of them corresponds to a second pin assignment. The north bridge chip includes a plurality of chip pins, and each of them corresponds to a first and second pin assignment. When the control circuit generates a first control signal, the pin assignments of the chip pins are defined as the first pin assignments. When the control circuit generates a second control signal, the pin assignments of the chip pins are defined as the second pin assignments.
It is an advantage of the present invention that, the computer system according the present invention comprises a 184 pin DIMM slot and a 168 pin DIMM slot, each with various pin assignments. The chip pins of the north bridge chip 16 separately correspond to the pin assignments of the 184 pin DIMM and of the 168 pin DIMM. Such allows a computer system with support for both DDRAM and SDRAM. During the transition from SDRAM to DDRAM, the users have not to worry about computer system upgrading and purchase decision of computer system.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiment, which is illustrated in the various figures and drawings.